Percutaneous spinal implants and methods

ABSTRACT

Apparatuses and methods for performing minimally invasive medical procedures are disclosed herein. In one example, an apparatus includes a first body coupled to a second body. The first body and the second body collectively configured to be releasably coupled to an implant device configured to be disposed between adjacent spinous processes. A first engaging portion is coupled to the first body, and a second engaging portion is coupled to the second body. The first engaging portion and/or the second engaging portion is configured to be received within a first opening defined by the implant device. The first body configured to be moved relative to the second body such that a distance between the first engaging portion and the second engaging portion is moved between a first distance and a second distance and simultaneously a length of the implant device is moved between a first length and a second length.

CROSS-REFERENCE TO RELATES APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 11/252,779, entitled “Percutaneous Spinal Implants and Methods,” filed Oct. 19, 2005 now abandoned; and U.S. patent application Ser. No. 11/252,880, entitled “Percutaneous Spinal Implants and Methods,” filed Oct. 19, 2005, now abandoned each of which is a continuation-in-part of U.S. patent application Ser. No. 11/059,526, entitled “Apparatus and Method for Treatment of Spinal Conditions,” filed Feb. 17, 2005 now abandoned and claims the benefit of U.S. Provisional Application Ser. No. 60/695,836 entitled “Percutaneous Spinal Implants and Methods,” filed Jul. 1, 2005, each of which is incorporated herein by reference in its entirety.

This application is related to U.S. patent application Nos. 11/356,294, 11/356,295, 11/356,301, and 11/356,302 each entitled “Percutaneous Spinal Implants and Methods,” and filed on even date herewith, each of which is incorporated herein by reference in its entirety.

BACKGROUND

The invention relates generally to percutaneous spinal implants, and more particularly, to percutaneous spinal implants for implantation, for example, between adjacent spinous processes.

A back condition that impacts many individuals is spinal stenosis. Spinal stenosis is a progressive narrowing of the spinal canal that causes compression of the spinal cord. Each vertebra in the spinal column has an opening that extends through it. The openings are aligned vertically to form the spinal canal. The spinal cord runs through the spinal canal. As the spinal canal narrows, the spinal cord and nerve roots extending from the spinal cord and between adjacent vertebrae are compressed and may become inflamed. Spinal stenosis can cause pain, weakness, numbness, burning sensations, tingling, and in particularly severe cases, may cause loss of bladder or bowel function, or paralysis. The legs, calves and buttocks are most commonly affected by spinal stenosis, however, the shoulders and arms may also be affected.

Mild cases of spinal stenosis may be treated with rest or restricted activity, non-steroidal anti-inflammatory drugs (e.g., aspirin), corticosteroid injections (epidural steroids), and/or physical therapy. Some patients find that bending forward, sitting or lying down may help relieve the pain. In some cases, bending forward may create more vertebral space, which may temporarily relieve nerve compression. Because spinal stenosis is a progressive disease, the source of pressure is often corrected surgically (e.g., decompressive laminectomy) when the patient has increasing pain over time. Known surgical procedures can remove bone and other tissues that have impinged upon the spinal canal or put pressure on the spinal cord. For example, two adjacent vertebrae can also be fused during the surgical procedure to prevent an area of instability, improper alignment or slippage, such as that caused by spondylolisthesis. Alternatively, surgical decompression can relieve pressure on the spinal cord or spinal nerve by widening the spinal canal to define more space. This procedure requires that the patient be given a general anesthesia because an incision is made in the patient to access the spine to remove the areas that are contributing to the pressure. This procedure, however, may result in blood loss and an increased chance of significant complications, and usually results in an extended hospital stay.

Known medical devices have been developed to be permanently implanted between spinous processes. Such devices, however, can be subject to wear or can cause collateral conditions that would necessitate the removal of the medical device. The removal of the medical device can be difficult to accomplish percutaneously.

Thus, a need exists for a device that can be implanted between spinous processes and configured to be reconfigurable such that the device can be removed or repositioned after implantation.

SUMMARY OF THE INVENTION

Apparatuses and methods for performing minimally invasive medical procedures are disclosed herein. In one example, an apparatus includes a first body coupled to a second body. The first body and the second body collectively configured to be releasably coupled to an implant device configured to be disposed between adjacent spinous processes. A first engaging portion is coupled to the first body, and a second engaging portion is coupled to the second body. The first engaging portion and/or the second engaging portion is configured to be received within a first opening defined by the implant device. The first body configured to be moved relative to the second body such that a distance between the first engaging portion and the second engaging portion is moved between a first distance and a second distance and simultaneously a length of the implant device is moved between a first length and a second length.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a medical device according to an embodiment of the invention in a collapsed configuration adjacent two spinous processes.

FIG. 2 is a schematic illustration of the medical device of FIG. 1 in an expanded configuration adjacent two spinous processes.

FIG. 3 is a side perspective view of an implant according to an embodiment of the invention in an expanded configuration.

FIG. 4 is a side perspective view of the implant of FIG. 3 shown in a collapsed configuration.

FIG. 5 is a side perspective view of the medical device of FIG. 3 shown in a collapsed configuration.

FIG. 6 is a side view of a deployment tool according to an embodiment of the invention.

FIG. 7 is a side view of a portion of the deployment tool of FIG. 6 shown in a first configuration.

FIG. 8 is a side view of the portion of the deployment tool of FIG. 7 shown in a second configuration.

FIG. 9 is a side view of a portion of the deployment tool of FIG. 7 and the implant of FIG. 3 with the implant shown in an expanded configuration.

FIG. 10 is a cross-sectional view of the portion of the deployment tool and implant shown in FIG. 9.

FIG. 11 is a cross-sectional view of the deployment tool and implant of FIG. 9 with the implant shown in a collapsed configuration positioned between adjacent spinous processes.

FIG. 12 is a side view of a portion of a medical device according to an embodiment of the invention illustrating an engaging portion in an extended configuration and positioned adjacent a spinous process.

FIG. 13 is a side view of the portion of the medical device of FIG. 12 illustrating the engaging portion in a partially collapsed configuration.

FIG. 14 is a side view of the portion of the medical device of FIG. 12 illustrating the engaging portion in the extended configuration after being inserted past the spinous process.

FIG. 15 is a side perspective view of the implant of FIG. 3 shown rotated about a longitudinal axis of the implant.

FIG. 16 is a side perspective view of an implant according to another embodiment of the invention.

FIG. 17 is a side view of a deployment tool according to another embodiment of the invention.

FIG. 18 is a side view of a deployment tool according to another embodiment of the invention.

FIG. 19 is a side view of a deployment tool according to another embodiment of the invention.

FIG. 20 is a side view of a deployment tool according to another embodiment of the invention.

FIG. 21 is a flow chart of a method according to an embodiment of the invention.

FIG. 22 is a side perspective view of an implant according to an embodiment of the invention shown in a collapsed configuration.

FIG. 23 is a cross-sectional view of the implant of FIG. 22 taken along line 23-23.

FIG. 24 is a cross-sectional view of the implant of FIG. 22 shown in an expanded configuration.

DETAILED DESCRIPTION

An apparatus (also referred to herein as a “medical device”) can be used in a variety of minimally-invasive (e.g., percutaneous, mini-open, endoscopic) medical procedures within a spine. The medical device may also be used for medical procedures performed in other areas of a patient. The following description discusses the use of the medical device for treatment of spinous processes as an example illustrating certain functionality and application of the device. It should be understood that procedures on other areas of a body, including other bone structures and soft tissue areas, may be performed with the medical device.

As used in this specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, the term “a member” is intended to mean a single member or a combination of members, “a material” is intended to mean one or more materials, or a combination thereof. Furthermore, the words “proximal” and “distal” refer to direction closer to and away from, respectively, an operator (e.g., surgeon, physician, nurse, technician, etc.) who would insert the medical device into the patient, with the tip-end (i.e., distal end) of the device inserted inside a patient's body first. Thus, for example, the implant end first inserted inside the patient's body would be the distal end of the implant, while the implant end to last enter the patient's body would be the proximal end of the implant.

In one embodiment, an apparatus includes a first body coupled to a second body. The first body and the second body collectively are configured to be releasably coupled to an implant device configured to be disposed between adjacent spinous processes. A first engaging portion is coupled to the first body, and a second engaging portion is coupled to the second body. The first engaging portion and/or the second engaging portion is configured to be received within a first opening defined by the implant device. The first body configured to be moved relative to the second body such that a distance between the first engaging portion and the second engaging portion is moved between a first distance and a second distance, and simultaneously a length of the implant device is moved between a first length and a second length.

In another embodiment, a kit includes an implant that is reconfigurable between an expanded configuration and a collapsed configuration while disposed between adjacent spinous processes. The implant has a longitudinal axis and defines an opening. A deployment tool is configured to be releasably coupled to the implant. The deployment tool includes an engaging portion configured to be removably received within the opening of the implant and extend in a transverse direction relative to the longitudinal axis when the deployment tool is coupled to the implant. The deployment tool is configured to move the implant between the collapsed configuration and the expanded configuration while the implant is disposed between the adjacent spinous processes.

FIGS. 1 and 2 are schematic illustrations of a medical device according to an embodiment of the invention positioned between two adjacent spinous processes. FIG. 1 illustrates the medical device in a first configuration, and FIG. 2 illustrates the medical device in a second configuration. The medical device 6000 includes an implant 6010 and a deployment tool 6020. The implant 6010 includes a distal portion 6012, a proximal portion 6014, and a central portion 6016. The implant 6010 is configured to be inserted between adjacent spinous processes S. The central portion 6016 is configured to contact and provide a minimum spacing between the spinous processes S when adjacent spinous processes S move toward each other during their range of motion to prevent over-extension/compression of the spinous processes S. In some embodiments, the central portion 6016 does not substantially distract the adjacent spinous processes S. In other embodiments, the central portion 6016 does distract the adjacent spinous processes S. The implant 6010 and the deployment tool 6020 can each be inserted into a patient's back and moved in between adjacent spinous processes from the side of the spinous processes (i.e., a posterior-lateral approach). The use of a curved insertion shaft assists in the use of a lateral approach to the spinous processes S.

The implant 6010 has a collapsed configuration in which the proximal portion 6014, the distal portion 6012 and the central portion 6016 share a common longitudinal axis. In some embodiments, the proximal portion 6014, the distal portion 6012 and the central portion 6016 define a tube having a constant inner diameter. In other embodiments, the proximal portion 6014, the distal portion 6012 and the central portion 6016 define a tube having a constant outer diameter and/or inner diameter. In yet other embodiments, the proximal portion 6014, the distal portion 6012 and/or the central portion 6016 have different inner diameters and/or outer diameters.

The implant 6010 can be moved from the collapsed configuration to an expanded configuration, as illustrated in FIG. 2. In the expanded configuration, the proximal portion 6014 and the distal portion 6012 each have a larger outer perimeter (e.g., outer diameter) than when in the collapsed configuration, and the proximal portion 6014 and the distal portion 6012 each have a larger outer perimeter (e.g., outer diameter) than the central portion 6016. In the expanded configuration, the proximal portion 6014 and the distal portion 6012 are positioned to limit lateral movement of the implant 6010 with respect to the spinous processes S. The proximal portion 6014 and the distal portion 6012 are configured to engage the spinous process (i.e., either directly or through surrounding tissue and depending upon the relative position of the adjacent spinous processes S) in the expanded configuration. For purposes of clarity, the tissue surrounding the spinous processes S is not illustrated.

In some embodiments, the proximal portion 6014, the distal portion 6012 and the central portion 6016 are monolithically formed. In other embodiments, one or more of the proximal portion 6014, the distal portion 6012 and/or the central portion 6016 are separate components that can be coupled together to form the implant 6010. For example, the proximal portion 6014 and distal portion 6012 can be monolithically formed and the central portion 6016 can be a separate component that is coupled thereto. These various portions can be coupled, for example, by a friction fit, welding, adhesive, etc.

The implant 6010 is configured to be coupled to the deployment tool 6020. The deployment tool 6020 includes an elongate member 6022 and two or more engaging portions 6024. In the embodiment shown in FIGS. 1 and 2, there are two engaging portions 6024-1 and 6024-2 shown, but it should be understood that more than two engaging portions 6024 can be included. The elongate member 6022 can include a first body portion 6026 coupled to a second body portion 6028. In some embodiments, the first body portion 6026 is threadedly coupled to the second body portion 6028. The first body portion 6026 and the second body portion 6028 are configured to be moved relative to each other. For example, a threaded connection between the first body portion 6026 and the second body portion 6028 can be used to decrease or increase a distance between the first body portion 6026 and the second body portion 6028. The first body portion 6026 and the second body portion 6028 can be a variety of different shapes and sizes, and can be the same shape and/or size, or have a different shape and/or size than each other. For example, in some embodiments, the first body portion includes a straight distal end and a straight proximal end, and the second body portion includes a straight proximal end and a curved or rounded distal end. The curved distal end can assist with the insertion of the deployment tool into a lumen of an implant and also with the insertion of the medical device into a portion of a patient's body.

The first engaging portion 6024-1 can be coupled to the first body portion 6026 and the second engaging portion 6024-2 can be coupled to the second body portion 6028. The engaging portions 6024 can be, for example, substantially rectangular, square, circular, oval, semi-circular, or quarter-moon shaped. The engaging portions 6024, can be spring-loaded devices coupled to the elongate member 6022 of the deployment tool 6020, such that the engaging portions 6024 are biased into a position transverse to a longitudinal axis A defined by the elongate member 6022 and extending from an outer surface of the elongate member 6022. Upon force exerted on the engaging portions 6024, the engaging portions 6024 can be moved or collapsed to a position substantially below the outer surface of the elongate member 6022. The engaging portions 6024 can alternatively be coupled to an actuator (not shown) configured to move the engaging portions 6024 from a position transverse to the longitudinal axis A and extending from an outer surface of the elongate member 6022, to a position substantially below the outer surface of the elongate member 6022.

FIGS. 12-14 illustrate the movement of an engaging portion 6024 as it passes by a spinous process S when an implant and deployment tool (collectively also referred to as medical device) are coupled together and being inserted between adjacent spinous processes. In some cases, as the medical device is being inserted, an engaging portion 6024 extending from a proximal portion of an implant may come into contact with a spinous process (or other tissue). To allow the engaging portion 6024 to pass by the spinous process, the engaging portion 6024 can be moved downward (as described above) so as to clear the spinous process. FIG. 12 illustrates an engaging portion 6024 having a spring-biased construction. The engaging portion 6024 includes a curved portion 6048 that initially contacts the spinous process S as the medical device is being inserted adjacent a spinous process S. As the curved portion 6048 contacts the spinous process S, the engaging portion 6024 is moved downward at least partially into an interior of the implant 6010, as shown in FIG. 13. The engaging portion 6024 moves back to an extended position (e.g., extending transversely from a surface of the implant 6010) after the engaging portion clears the spinous process S, as shown in FIG. 14, due to the bias of the spring (not shown).

The deployment tool 6020 can be used to move the implant 6010 from the collapsed configuration to the expanded configuration, and vice versa, as will be discussed in more detail below. The first body portion 6026 and the second body portion 6028 are collectively configured to be inserted at least partially into a lumen (not shown in FIGS. 1 and 2) of the implant 6010, such that at least one engaging portion 6024 extends through an opening (not shown in FIGS. 1 and 2) defined by the implant 6010. The implant 6010 can be configured with one or more such openings, each of which is configured to receive an engaging portion 6024 disposed on the elongate member 6022 (e.g., the first body portion 6026 or the second body portion 6028). The openings defined by the implant 6010 can be, for example, the openings can be circular, oval, square, rectangular, etc. FIG. 3 illustrates an example of an implant 6110 defining curved rectangular openings 6136, and FIG. 16 illustrates an implant 6310 defining curved round or circular openings 6336.

The openings are at least partially defined by an edge (not shown in FIGS. 1 and 2) on the implant 6010. The engaging portions 6024 on the deployment tool 6020 include a surface (not shown in FIGS. 1 and 2) that is configured to engage or contact the edge of the openings of the implant 6010 when the elongate member 6022 is inserted into the lumen of the implant 6010.

In use, the spinous processes S can be distracted prior to inserting the implant 6010. Distraction of spinous processes is disclosed, for example, in U.S. application Ser. No. 11/059,526, incorporated herein by reference in its entirety. When the spinous processes are distracted, a trocar can be used to define an access passage for the implant 6010. In some embodiments, the trocar can be used to define the passage as well as distract the spinous processes S. Once an access passage is defined, the implant 6010 can be inserted percutaneously and advanced between the spinous processes, distal end 6012 first, until the central portion 6016 is located between the spinous processes S. In some embodiments, the implant 6010 can be coupled to the deployment tool 6020 prior to being inserted between the adjacent spinous processes. In other embodiments, the implant 6010 can be inserted between adjacent spinous processes without being coupled to the deployment tool 6020. In the latter configuration, after the implant 6010 is disposed between the adjacent spinous processes, the deployment tool 6020 can be inserted into the lumen defined by the implant 6010.

Once the implant 6010 is in place between the spinous processes, and the deployment tool 6020 is in position within the lumen of the implant 6010, the implant 6010 can be moved to the second configuration (i.e., the expanded configuration) by actuating the deployment tool 6020. For example, when the deployment tool 6020 is inserted into the lumen of the implant 6010, the first body portion 6026 is positioned at a first distance from the second body portion 6028, and the first engaging portion 6024-1 is positioned at a first distance from the second engaging portion 6024-2, as shown in FIG. 1. The deployment tool 6020 can then be actuated at a proximal end portion (e.g., by turning a handle) (not shown in FIGS. 1 and 2) causing the threaded coupling between the first body portion 6026 and the second body portion 6028 to move the first body portion 6026 and the second body portion 6028 towards each other such that the first body portion 6026 is now at a second distance (closer) from the second body portion 6028, as shown in FIG. 2. This movement likewise moves the first engaging portion 6024-1 and the second engaging portion 6024-2 to a closer position relative to each other. For example, in FIG. 1, the first engaging portion 6024-1 is positioned at a distance from the second engaging portion 6024-2 that is greater than a distance between the first engaging portion 6024-1 and the second engaging portion 6024-2 shown in FIG. 2.

As the engaging portions 6024-1 and 6024-2 are moved relative to each other, the surface (described above and described in more detail below) on the engaging portions 6024 imparts a force on the edge (described above and described in more detail below) of the opening defined by the implant causing the implant to move from the collapsed configuration to the expanded configuration.

The deployment tool 6020 is configured such that the deployment tool 6020 can be removed from the implant 6010 after the implant has been moved to the expanded configuration. The implant can remain disposed between the spinous processes indefinitely or removed as needed. For example, the deployment tool 6020 can be reinserted into the lumen of the implant 6010 and actuated in an opposite direction to cause the implant 6010 to be moved from the expanded configuration back to the collapsed configuration. In the collapsed configuration, the implant can be removed from the patient's body or repositioned to a new location between the spinous processes.

In some embodiments, the implant 6010 is inserted percutaneously (i.e., through an opening in the skin) and in a minimally-invasive manner. For example, as discussed in detail herein, the sizes of portions of the implant are expanded after the implant is inserted between the spinous processes. Once expanded, the sizes of the expanded portions of the implant are greater than the size of the opening. For example, the size of the opening/incision in the skin can be between 3 millimeters in length and 25 millimeters in length across the opening. In some embodiments, the size of the implant in the expanded configuration is between 3 and 25 millimeters across the opening.

FIGS. 3-5 illustrate an implant according to an embodiment of the invention. An implant 6110 includes a proximal portion 6114, a distal portion 6112, and a central portion 6116. The implant 6110 also defines multiple openings 6132 on an outer surface of the implant 6110. The openings 6132 are in communication with a lumen 6158 (shown in FIG. 10) defined by the implant 6110. The openings 6132 are partially defined by a first edge 6136 and a second edge 6138. The implant 6110 includes expandable portions disposed at the distal portion 6112 and the proximal portion 6114. The expandable portions 6140 can be coupled to the implant 6110 or formed integral with the implant 6110, as shown in FIG. 15. As shown in FIG. 15, elongated slots 6134 can be defined on an outer surface of the implant 6110. The elongated slots 6134 create weakened areas on the implant 6110 that allow the expandable portions 6140 to fold when exposed to axial force, forming extensions 6142, as shown in FIG. 4.

The implant 6110 can be inserted between adjacent spinous processes (not shown) in a collapsed configuration, as shown in FIG. 3, and then moved to an expanded configuration, as shown in FIG. 4. The implant 6110 can then be moved back to a collapsed configuration as shown in FIG. 5, which illustrates the expandable portions 6140 in a partially collapsed configuration. Although FIG. 5 shows a partially collapsed configuration, in some embodiments, the implant can be moved back to the collapsed configuration as shown in FIG. 3.

To move the implant 6110 from the collapsed configuration to the expanded configuration, and vice versa, a deployment tool, as described above and as shown in FIGS. 6-8, can be used. The deployment tool 6120 includes an elongate member 6122 coupled to a handle 6144. The elongate member 6122 includes a first body portion 6126 coupled to a second body portion 6128 through a threaded coupling 6150. A pair of engaging portions 6124-1 are disposed on the first body portion 6126, and a pair of engaging portions 6124-2 are disposed on the second body portion 6128. The engaging portions 6124-1 and 6124-2 (also collectively referred to as engaging portions 6124) include a surface 6146 and a rounded portion 6148. The threaded coupling 6150 between the first body portion 6126 and the second body portion 6128 is used to move the first body portion 6126 and the second body portion 6128 such that a distance between the first body portion 6126 and the second body portion 6128 is changed. For example, FIG. 7 illustrates a first distance d-1 between the first body portion 6126 and the second body portion 6128, and FIG. 8 illustrates a second distance d-2 between the first body portion 6126 and the second body portion 6128. As shown in FIGS. 7 and 8, as the distance between the first body portion 6126 and the second body portion 6128 is changed, a distance between the engaging portions 6124-2 and 6124-2 is also changed.

In use, the first body portion 6126 and the second body portion 6128 are collectively disposed within the lumen 6158 of the implant 6110, such that the engaging portions 6124 extend through the openings 6132 and transverse to an axis B defined by the implant 6110, as shown in FIGS. 9-11. In this position, the surface 6146 of the engaging portions 6124 is configured to contact the edge 6136 of the openings 6132. FIGS. 9 and 10 illustrate the first body portion 6126 and the second body portion 6128 disposed within the lumen of the implant 6110, when the implant is in a collapsed configuration. In this position, the first body portion 6126 is at a first distance from the second body portion 6128, the engaging portions 6124-1 are at a first distance from the engaging portions 6124-2, and the implant has a first length L-1.

When the implant is positioned between spinous processes S, the deployment tool 6120 can be actuated to move the implant 6110 to the expanded configuration, as shown in FIG. 11. When the deployment tool 6120 is actuated, the first body portion 6126 is moved closer to the second body portion 6128, and the engaging portions 6124-1 are moved closer to the engaging portions 6124-2. When this occurs, the surface 6146 on the engaging portions 6124 impart a force on the edge 6136 of the openings 6132, which axially compresses the implant 6110 until the implant 6110 has a second length L-2, as shown in FIG. 11.

To move the implant 6110 back to the collapsed configuration, the deployment tool 6120 can be reconfigured such that the surface 6146 of the engaging portions 6124 are positioned facing an opposite direction and configured to contact the edge 6138 of the implant 6110, as shown in FIG. 20. In some embodiments, the engaging portions 6124 can be, for example, removed and re-coupled to the elongate member 6122 (e.g., the first body portion 6126 and the second body portion 6128) such that the same engaging portions 6124 are simply repositioned. In other embodiments, a second deployment tool can be used having engaging portions positioned in the opposite direction. In either case, the deployment tool is inserted into the lumen 6158 of the implant 6110 as done previously, such that the engaging portions 6124 extend through the openings 6132 of the implant 6110 and the surface 6146 contacts the edge 6136 of the implant 6110. The deployment tool 6120 is then actuated in an opposite direction (e.g., turned in an opposite direction) such that the first body portion 6126 and the second body portion 6128 are threadedly moved further away from each other. In doing so, the engaging portions 6124-1 are moved further away from the engaging portions 6124-2, and the surface 6146 of the engaging portions 6124 impart a force on the edge 6138 (instead of edge of 6136) of openings 6132, which moves the implant 6110 back to the collapsed or straightened configuration. Thus, the implant described in all of the embodiments of the invention can be repeatedly moved between the collapsed and expanded configurations as necessary to insert, reposition or remove the implant as desired.

FIG. 17 illustrates a deployment tool according to another embodiment of the invention. A deployment tool 6220 includes an elongate member 6222 having a first body portion 6226 coupled to a second body portion 6228 through a threaded coupling 6250. In this embodiment, the deployment tool 6220 includes two sets of four (8 total) engaging portions 6224 (only six engaging portions are shown in FIG. 17). A first set of engaging portions 6224-1 are coupled to the first body portion 6226, and a second set of engaging portions 6224-2 are coupled to the second body portion 6228. The engaging portions 6224 include a first surface 6246 and a second surface 6252. When the deployment tool 6220 is coupled to an implant, the first surface 6246 is configured to contact an edge of an opening defined on the implant (such as edge 6136 on implant 6110), and the second surface 6252 is configured to contact an opposite edge on the opening defined by the implant (such as edge 6138 on implant 6110).

Thus, in this embodiment, the deployment tool 6220 can be inserted into an implant and used to move the implant between a collapsed configuration and an expanded configuration without having to reposition the engaging portions 6224, or use a second deployment tool. To move the implant from a collapsed configuration to an expanded configuration, the deployment tool 6220 is actuated in a first direction. To move the implant back to the collapsed configuration, the deployment tool 6220 is actuated in an opposite direction (e.g., turned in an opposite direction). When the deployment tool 6220 is actuated to move the implant from the collapsed configuration to the expanded configuration, the surface 6246 of the engaging portions 6224 impart a force on an edge of an opening (e.g., edge 6136 on implant 6110), causing the implant to be axially compressed, as previously described. When the deployment tool 6220 is actuated to move the implant from the expanded configuration to the collapsed configuration, the surface 6252 of the engaging portions 6224 imparts a force on an opposite edge of the opening (e.g., edge 6138 on implant 6110), causing the implant to be substantially straightened as previously described.

FIG. 18 illustrates a deployment tool according to another embodiment of the invention. A deployment tool 6420 is similar to the deployment tool 6220 described above, except in this embodiment, there are only two sets of two engaging portions 6424 (4 total). The engaging portions 6424 are similar to the engaging portions 6224 except the engaging portions 6424 are substantially rectangular shaped. The engaging portions 6424 include a surface 6446 configured to contact an edge of an opening defined by an implant, and a surface 6452 configured to contact an opposite edge of the opening defined by the implant.

FIG. 19 illustrates a deployment tool according to yet another embodiment of the invention. A deployment tool 6520 is similarly constructed and functions similarly to the previous embodiments. The deployment tool 6520 includes an elongate member 6522 that includes a first body portion 6526 and a second body portion 6528. In this embodiment, the first body portion 6526 and the second body portion 6528 are smaller than illustrated in the previous embodiments, and engaging portions 6524 are coupled to the first body portion 6526 and the second body portion 6528 that are more elongate than previously shown.

A kit according to an embodiment of the invention can include at least one implant and at least one deployment tool as described above. For example, a kit can include an implant and two deployment tools, one deployment tool configured to be used to move the implant from a collapsed configuration to an expanded configuration, and another deployment tool configured to be used to move the implant from the expanded configuration to the collapsed configuration. Alternatively, a kit can include a single deployment tool have multiple engaging portions as described herein, that can be releasably coupled to an elongate member of a deployment tool. For example, one type or style of engaging portion can be used to move the implant from a collapsed configuration to an expanded configuration, and another type or style of engaging portion can be used to move the implant from the expanded configuration to the collapsed configuration. The kit can include engaging portions having one of a variety of different shapes and sizes, such that a user can select a particular engaging portion(s) for use in a particular application.

FIGS. 22-24 illustrate an implant according to another embodiment of the invention. An implant 6610 includes an outer shell 6670 having a distal portion 6612, a proximal portion 6614, and a central portion 6616. The implant 6610 can be moved between a collapsed configuration as shown in FIGS. 22 and 23, and an expanded configuration, as shown in FIG. 24. The proximal portion 6614 and the distal portion 6612 include expandable portions 6640 that form extensions 6642 that extend radially from the outer shell 6670 when the implant 6610 is in the expanded configuration.

The implant 6610 also includes an inner core 6672 disposed within a lumen 6658 defined by the outer shell 6670. The inner core 6672 can be constructed to provide increased compressive strength to the central portion 6616 of the outer shell 6670. In some embodiments, the inner core 6672 can define a lumen, while in other embodiments, the inner core 6672 can have a substantially solid construction. The inner core 6672 can be coupled to the central portion 6616 of the outer shell 6670 by, for example, a friction fit. The inner core 6672 can have a length such that the inner core 6672 is disposed within the lumen 6658 along substantially the entire length of the outer shell 6670 or only a portion of the length of the outer shell 6670. The inner core 6672 is also coupled to the distal portion 6612 of the outer shell 6670 with a coupling member 6674.

The coupling member 6674 can be, for example, a threaded coupling that can be used to move the implant 6610 between the collapsed configuration and the expanded configuration. For example, when the implant 6610 is disposed between adjacent spinous processes, a device can be used to turn the coupling member 6674 in a first direction such that an axial force is imparted on the distal portion 6612 of the outer shell 6610 in a proximal direction, and the distal portion 6612 is drawn toward the proximal portion 6614. In doing this, the outer shell 6670 will fold or bend as described in previous embodiments, and the implant 6610 will be moved to the expanded configuration. To move the implant 6610 from the expanded configuration to the collapsed configuration, the coupling member 6674 is turned in an opposite direction to impart an axial force on the distal portion 6612 of the outer shell 6610 in a distal direction, moving the distal portion 6612 distally, and moving the implant 6610 to the collapsed configuration.

FIG. 21 is a flow chart illustrating a method according to an embodiment of the invention. A method includes at 6060, percutaneously disposing an expandable member at a first location between adjacent spinous processes within a body of a patient while the expandable member is in a collapsed configuration. The expandable member is coupled to a deployment tool that includes an engaging portion configured to be received through an opening defined by the expandable member. In other embodiments, the deployment tool can be coupled to the implant after the implant has been disposed between the spinous processes. After the implant has been disposed between the adjacent spinous processes, the expandable member can be moved from the collapsed configuration to an expanded configuration at 6062. To do this, the deployment tool can be actuated while the expandable member is disposed between the adjacent spinous processes such that the engaging portion of the deployment tool imparts a force to a first location on the expandable member and causes the expandable member to move from the collapsed configuration to an expanded configuration. After actuating the deployment tool such that the expandable member is moved from the collapsed configuration to the expanded configuration, the deployment tool can optionally be removed from the expandable member, at 6064. In embodiments where the deployment tool has been removed, the deployment tool can be subsequently reinserted into the expandable member.

At 6066, after the deployment tool has been actuated to move the implant from the collapsed configuration to the expanded configuration, the deployment tool can be actuated again such that the engaging portion imparts a force to a second location on the expandable member different from the first location on the expandable member, and the implant is moved from the expanded configuration to the collapsed configuration.

After actuating the deployment tool such that the expandable member is moved from the expanded configuration to the collapsed configuration, the expandable member can optionally be disposed at a second location between the adjacent spinous processes different from the first location, at 6068. In some embodiments, after the deployment tool is actuated such that the expandable member is moved from the expanded configuration to the collapsed configuration, the expandable member can optionally be disposed at a second location outside of the body of the patient, at 6070.

The various implants and deployment tools described herein can be constructed with various biocompatible materials such as, for example, titanium, titanium alloyed, surgical steel, biocompatible metal alloys, stainless steel, plastic, polyetheretherketone (PEEK), carbon fiber, ultra-high molecular weight (UHMW) polyethylene, biocompatible polymeric materials, etc. The material of a central portion of the implant can have, for example, a compressive strength similar to or higher than that of bone. In one embodiment, the central portion of the implant, which is placed between the two adjacent spinous processes, is configured with a material having an elastic modulus higher than the elastic modulus of the bone, which forms the spinous processes. In another embodiment, the central portion of the implant is configured with a material having a higher elastic modulus than the materials used to configure the distal and proximal portions of the implant. For example, the central portion of the implant may have an elastic modulus higher than bone, while the proximal and distal portions have a lower elastic modulus than bone. In yet another embodiment, where the implant is configured with an outer shell and an inner core. The outer shell can be configured with material having a higher elastic modulus than the inner core (e.g., outer shell is made with titanium alloyed, while the inner core is made with a polymeric material). Alternatively, the outer shell can be configured with a material having a lower elastic modulus than the inner core (e.g., the outer shell is made with a polymeric material while the inner core is made with a titanium alloyed material).

With at least some of the medical devices described herein, the location of the expandable portions of the implant can be selected in vivo, rather than having predetermined expansion locations. Such a configuration reduces the need to have multiple sizes of spacers available. Additionally, the timing of the deployment of the protrusions can be varied.

While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art having the benefit of this disclosure would recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Thus, the breadth and scope of the invention should not be limited by any of the above-described embodiments, but should be defined only in accordance with the following claims and their equivalents. While the invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood that various changes in form and details may be made.

For example, although the embodiments above are primarily described as being spinal implants configured to be positioned between adjacent spinous processes, in alternative embodiments, the implants are configured to be positioned adjacent any bone, tissue or other bodily structure where it is desirable to maintain spacing while preventing axial or longitudinal movement of the implant.

While the implants described herein were primarily described as not distracting adjacent spinous processes, in alterative embodiments, the implants can be configured to expand to distract adjacent spinous processes. Although described as being inserted directly between adjacent spinous processes, in alternative embodiments, the implants described above can be delivered through a cannula. 

1. An apparatus, comprising: an implant device comprising an outer shell and an inner body disposed in a lumen of the outer shell; a distal portion of the inner body configured to apply an axial load on the outer shell to deform at least a portion of the outer shell from a collapsed configuration to an expanded configuration, the outer shell configured for placement between adjacent spinous processes; the outer shell having a central portion, an expandable proximal portion, an expandable distal portion, and a longitudinal axis extending-through a center of the lumen from the expandable proximal portion to the expandable distal portion; wherein in the expanded configuration, the proximal and distal expandable portions both extend farther away from the longitudinal axis than the central portion; wherein the central portion extends the substantially same distance from the longitudinal axis in both the collapsed and the expanded configurations.
 2. The apparatus of claim 1 wherein the central portion is configured to distract the adjacent spinous processes.
 3. The apparatus of claim 1 wherein the distal portion of the inner body is configured to apply the axial load to expand the expandable distal portion and the expandable proximal portion of the outer shell.
 4. The apparatus of claim 3 wherein the distal portion of the inner body is configured to apply the axial load to simultaneously expand the expandable distal portion and the expandable proximal portion of the outer shell.
 5. The apparatus of claim 3 wherein the distal portion of the inner body is configured to apply the axial load to expand the expandable distal portion and the expandable proximal portion of the outer shell sequentially.
 6. The apparatus of claim 1 wherein, in the collapsed configuration, the expandable proximal portion, the expandable distal portion, and the central portion of the outer shell extend approximately the same length from the longitudinal axis. 